the low ph of the earth juice tends to keep it from expiring. The acidic solution keeps bacteria from growing (my guess) I was told by earth juice that it is not even necessary to use caps on the product. It is completely stable and will not go bad unless its in an extreme environment. They keep samples of every batch ever made for 10 years and according to them the product will not expire.
Earthjuice has never done me wrong and it has a way of making your buds extra smelly. High brix that your plants will love.